I have been spending a lot of time going SEO for my company site Mingo Smart Factory. When revamping the site architecture; I created a category hierarchy and category pages.
By default, Yoast uses the post excerpt for the meta description. But on a category page there is no post body for the system to create an excerpt from—only the description of a category.
Below is the Yoast configuration for this category page. You can see that I created a custom description for this page rather than having Yoast generate it.